---
name: "cgrules.conf"
section: "5"
platform: "linux"
package: "cgroup-tools"
version: "3.1.0-2+b2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/cgrules.conf"
---

# cgrules.conf(5)

libcgroup configuration file

## NAME

cgrules.conf - libcgroup configuration file

## DESCRIPTION

**cgrules.conf** configuration file is used by **libcgroups** to define control groups to which a process belongs.

The file contains a list of rules which assign to a defined group/user a control group in a subsystem (or control groups in subsystems).

Rules have two formats:

```
<user>               	<controllers>		<destination>
```

```
<user>:<process name>	<controllers>		<destination>
```

Where:

*user* can be:

```
    - a user name
    - a group name with @group syntax
    - the wildcard '*', for any user or group
    - '%', which is equivalent to "ditto" (useful for
      multi-line rules where different cgroups need to be
      specified for various hierarchies for a single user)
```

*process name* is optional and it can be:

```
    - a process name
    - a full command path of a process
```

*controllers* can be:

```
    - comma separated controller names (no spaces) or
    - * (for all mounted controllers)
```

*destination* can be:

```
    - path relative to the controller hierarchy (ex. pgrp1/gid1/uid1)
    - following strings called "templates" and will get expanded
          %u     uid
          %U     username, uid if name resolving fails
          %g     gid
          %G     group name, gid if name resolving fails
          %p     pid
          %P     process name, pid if name not available
          '\' can be used to escape '%'
```

First rule which matches the criteria will be executed.

Any text starting with '#' is considered as a start of comment line and is ignored.

If the *destination* contains **template** string, the control group can be created on-fly. In time when some process wants to use the template rule which leads to control group (see **cgexec** (1)) and the control group does not exist, the group is created. The template control group parameters can be specified in **cgconfig.conf** configuration file. See (**cgconfig.conf** (5)). If the template definition is not found there created group have default kernel setting.

To create a hierarchy of configuration files, use **/etc/cgrules.d** directory.

## EXAMPLES

```
student         devices         /usergroup/students
```

Student's processes in the 'devices' subsystem belong to the control group /usergroup/students.

```
student:cp       devices         /usergroup/students/cp
```

When student executes 'cp' command, the processes in the 'devices' subsystem belong to the control group /usergroup/students/cp.

```
@admin           *              admingroup/
```

Processes started by anybody from admin group no matter in what subsystem belong to the control group admingroup/.

```
peter           cpu             test1/
%               memory          test2/
```

The first line says Peter's task for cpu controller belongs to test1 control group. The second one says Peter's tasks for memory controller belong to test2/ control group.

```
*               *               default/
```

All processes in any subsystem belong to the control group default/. Since the earliest matched rule is applied, it makes sense to have this line at the end of the list. It will put a task which was not mentioned in the previous rules to default/ control group.

```
@students	cpu,cpuacct	students/%u
```

Processes in cpu and cpuacct subsystems started by anybody from students group belong to group students/name. Where "name" is user name of owner of the process.

## FILES

- **/etc/cgrules.conf**

  default libcgroup configuration file

- **/etc/cgrules.d**

  default libcgroup configuration files directory

## SEE ALSO

cgconfig.conf (5), cgclassify (1), cgred.conf (5), cgrules.d (5)

## BUGS